if you own the community you can do anything like allowing or forbidding base64 arbitrary data in your own community. But by default we limit all comments to 40kb. We use IPFS because its the best framework for a global content-addressable p2p network, they also have IPNS (mutable names) which is the basis of our protocol community names. We dont use any DNS/TLS within our core protocol, everything is signed and verified by using IPFS and IPNS primitives. More info about IPNS here,

IPNS (InterPlanetary Name System) | IPFS Docs

Learn about mutability in IPFS, InterPlanetary Name System (IPNS), and how it can be used in conjunction with IPFS.